FileAnt is a Windows File Manager (like explorer) on tabs (like UltraEdit-32), it is also a cool Ftp Client (like leechftp) and has nice features such as folder pie charts, and a viewer for commonly used file formats. It loads quickly from the tray and uses very little memory to achieve what it does.
The Ftp Client is multi-download (you can keep browsing while downloading lots of files). The Pie Chart features 2D telescopic browsing. Advanced tools let you modify file dates, sync folders, and change file attributes en masse. There is also a nice little mp3 player in the tray.